Pictured here is the Keypad Gemstick. It was made by Gemini for the Colecovision. Gemini made controllers for the Atari 2600 as well. (As best I know, there is no relationship between Gemini and Coleco's Atari 2600 compatible console named Gemini.)
This controller is a beige version of Amiga's Power Stick for the Colecovision (which is black with red buttons). I am unable to prove it, but I believe Gemini bought the rights to the design from Amiga post-Crash. Gemini also released a beige version of the Atari 2600 Power Stick originally sold by Amiga (which is also black with red buttons).
It's hard to tell from the picture, but the keypad portion is on an angle such that the top row of numbers is much thicker than the bottom row where it meets the joystick. The lettering at the bottom on the front says "Keypad / Gemstick." The sticker on the back shows the inspection number and "Made in Taiwan R.O.C." The inset shows the Gemini name on the back. The red square indicates the portion shown in the inset.
Thanks to Digital Press and Alexander Bilstein for some of the above information. You can see the Atari 2600 Power Stick in the Gallery of Alexander's Atari 2600 Nexus.