They appear to be hand made and the slots are off center. The same type screw was used on the candle holder and the bottom.
One of the candle holders got burned a little. They are 11.5" tall and 7"wide.
The screw mechanism to lower the candles is nicely turned. The item "Pair American Adjustable Figured Maple Candlestick. Late 18th Early 19th Century" is in sale since Monday, May 6, 2019. This item is in the category "Antiques\Furniture\Chairs\Pre-1800". The seller is "bestofnewengland" and is located in Sunapee, New Hampshire.This item can be shipped to United States.