You better send him a 70s vintage car with the safety windshield and a big bottle of superslick too.

Hey, I was close. I had seen this tool in my past. When I was a youngen' I got to occasionally hang out in my uncles glass business and watch them replace windows in all kinds of stuff....cars, trucks, homes, businesses, you name it. I remember seeing this tool, but I didn't remember the exact use.

Coolest trick I ever saw was my uncle use a piece of clothesline cord to replace a windshield in my brother's VW beetle some 20 years ago. He made it look easy.

I gotta check in more often! I worked in an auto glass shop. This tool is as Rusty said for windshields. However it is for the one piece gasket type of rubber where one lip is worked under the other lip to lock it in place, common on all kinds of cars, trucks, buses, construction equipment. The tip is worked in between and the roller rolls the "loose" lip under the locking lip. These gaskets were used on any stationary window - windshield, rear window, side or quarter glasses, any non-moving window. Use of vaseline, mineral spirits, gasoline(obviously NOT a good idea) to lubricate the rubber and keep the tool moving.  The other tool pictured with a loop at the end is for the gaskets that used a separate locking round rubber strip.  The rubber strip was fed through the loop as you worked it along the window. Either way, locking in curved windows was always challenging. Al.