Description This Knocking Equations Big Bang Theory Shirt features the mathematical equation for the way Sheldon knocks on Penny's door. Sheldon is standing above the equation while wearing a Green Lantern shirt in front of a Fibonacci Spiral.

This Big Bang Theory White t-shirt features the Knock Knock Knock Plus Penny Times 3 printed on the front of the Tee Shirt.Available in Small, Medium, Large, XL & 2XL!Officially Licensed!

Description This Big Bang Theory shirt features a repetition of the words Knock Knock Knock Penny!. When Sheldon visits Penny he announces himself by summoning Penny and knocking three times. He repeats this pattern until an exasperated or amused Penny finally opens the door.   

This is an officially licensed Big Bang Theory product. This t-shirt says "Knock! Knock! Knock! + [picture of Penny] X 3"

Alkaline Trio Knocked Out Heart Women's T-shirt

If Opportunity Knocks T-Shirt is in stock and ready to ship from Tshirtoutlet.com. We stock If Opportunity Knocks T-Shirt for $14.95. We appreciate your order.

Zappos.com is proud to offer the Volcom Kids - Knock Stripe S/S Tee (Big Kids) (Vintage Navy) - Apparel: A great opportunity to keep it cool with this Volcom Kids tee. ; Cotton/poly blend knit tee for great comfort. ; Allover stripe. ; Stone logo appears at front chest. ; Crew neck pullover. ; Short sleeves. ; Single contrast stripe goes against the norm. ; Straight hemline. ; 50% polyester, 37% cotton, 13% rayon. ; Machine wash cold, tumble dry low. ; Imported. ; Length: 24 in ; Product measurements were taken using size SM (8 Big Kids). Please note that measurements may vary by size.

Zappos.com is proud to offer the Volcom Kids - Knock Stripe S/S Tee (Big Kids) (Regatta Blue) - Apparel: A great opportunity to keep it cool with this Volcom Kids tee. ; Cotton/poly blend knit tee for great comfort. ; Allover stripe. ; Stone logo appears at front chest. ; Crew neck pullover. ; Short sleeves. ; Single contrast stripe goes against the norm. ; Straight hemline. ; 50% polyester, 37% cotton, 13% rayon. ; Machine wash cold, tumble dry low. ; Imported. ; Length: 24 in ; Product measurements were taken using size SM (8 Big Kids). Please note that measurements may vary by size.

Big Bang Theory Knock Equation T Shirt This is an officially licensed Big Bang Theory t-shirt.

Star Wars Knock Out T Shirt This is an officially licensed Star Wars t-shirt.

Women's: Alkaline Trio - Knocked out heart

Big Bang Theory - Knock Knock Knock + Penny x3

Big Bang Theory - Penny Knock Knock

"Knock, knock, knock, ""Penny?"" Any fan of the hit sitcom ""The Big Bang Theory"" will instantly recognize Sheldon's trademark knocking pattern from his frequent visits to Penny's apartment. Order your t-shirt now, and start annoying your neighbors with your attire in addition to your Asperger's. Black 100% Cotton Officially Licensed Standard Fit More 'The Big Bang Theory' items: The Big Bang Theory Merchandise"

Artist: HVW8 (Charles Munka) ; Title: Double Knock Out ; Brand: HVW8

Officially licensed Big Bang Theory Penny x3 Knock White Tee Shirt. Features an image of Penny and says, 'Knock + Penny x 3' 100% cotton.

Officially licensed Big Bang Theory Penny Knock Black TShirt. Features a bold white print that repeats, 'PENNY! Knock knock knock.' 100% cotton.

"We find out in The Cooper-Nowitzki Theorem that Sheldon knows Morse code (""I'm invoking the Skynet clause of our friendship agreement.""). That means the three short taps in the triple-Penny-knock could be the S of ""SOS."" Or possibly he's hissing like a deflated bicycle tire. Or maybe it's an ""s"" like in ""Pssssssst!"" That works. That way the knock both performs the function of getting the intended recipient's attention and also communicating information about the nature of the conversation. Okay. Maybe not. One thing we do know for sure is you don't want to ignore him. Cause he ain't going away. ""knock knock knock Penny! knock knock knock Penny! knock knock knock Penny!"" in white on a black 100% cotton t-shirt. And also, it's in all caps but we didn't do that here because we didn't want to look like we were yelling at you. But you should feel free to yell at people reading your t-shirt. You might notice in the action shots that there was once a version that had ""Penny!"" fir

The Big Bang Theory Knock Knock Knock Penny T Shirt

This Muhammad Ali T-shirt is an exceptional 100% cotton preshrunk T-shirt for any Muhammad Ali Fan . Muhammad Ali was a well known world heavyweight champion. Muhammad Ali was known as The Greatest.Available in Small, Medium, Large, XL & 2XL!Officially Licensed!

Trust me, this is a good shirt

Awesome retro Barack Obama t-shirt. Ladies Love Obama!You'll love the super soft feel of this premium ring-spun cotton fabric. Our funny t-shirts are sure to please. Most of our tees have a slightly tapered fit; size up for more room.

Abstract Fox text logo on front with Fox head logo. Short sleeve. Crew neck. 100% cotton. Machine wash. Imported.

Big Bang Theory Penny T Shirt This is an officially licensed Big Bang Theory t-shirt.